Note that the archive is constantly growing; testing will grow especially
as a release approaches. Also, we do not recommend reducing size of a mirror
by excluding specific distributions; exclude specific architectures instead,
according to their popularity.

How big is the Debian CD archive?

The CD archive varies greatly across mirrors — the Jigdo files are
around 100-150 MB per architecture, while the full DVD/CD images are
around 15 GB each, plus extra space for the update CD images,
Bittorrent files, etc.